interface Ikun {
  name: string;
  age: number;
  slogan?: string;
}

type t1 = "上海" | "北京" | "洛杉矶";

// Keys extends keyof any: 返回联合类型

type MyRecord<Keys extends keyof any, O> = {
  // in 联合类型（in keyof 对象，keyof返回的就是返回联合类型）
  [P in Keys]: O;
};

type IkunOptional = Record<t1, Ikun>;
type IkunOptional1 = MyRecord<t1, Ikun>;

export {};
